1. (Deoxyribonucleic Acid)

2. DNA makes up the chromosomes of a cell.

3. It is the blueprints for how to make all of the proteins in the organism

4. Things that are made of proteins: skin, hair, blood, cells, and so on… (everything that you are made of!!)

5. James Watson and Francis Crick were the scientists that discovered the actual structure of DNA

6. They found that DNA is a double helix(a double spiral)

7. DNA looks a little bit like a spiral staircase…

8. Sugar phosphate Backbone
Nitrogen bases
Sugar phosphate Backbone

9. The handrails of DNA are made of sugar and phosphate

10. The stairs of DNA are made of nitrogen bases.

11. We say that DNA is composed of building blocks called NUCLEOTIDES.

12. A nucleotide is made of:
a 5- carbon sugar (pentose)called deoxyribose
a phosphate group
a base (any one of four different kinds

13. The phosphate bonds to the sugar, forming a “backbone” of sugars and phosphates.

14. A base attaches to each sugar, so that the nucleotides form a chain.

15. Adenine, Thymine, Cytosine, and Guanine
There are four bases:
Adenine, Thymine, Cytosine, and Guanine

16. Sugar phosphate Backbone
Adenine
Guanine
Thymine
Cytosine
Phosphate
Sugar

17. Adenine always bonds with Thymine

18. Sugar phosphate Backbone
Adenine
Thymine
Phonsphate
Sugar

19. Guanine always bonds with Cytosine

20. Sugar phosphate Backbone
Guanine
Cytosine
Phosphate
Sugar

21. Since DNA is a DOUBLE HELIX, it has two strands.

22. The strands are COMPLEMENTARY to each other (the complement of each base is directly across from it).

23. You can figure out what the structure of the complementary strand of DNA will be if you are given the original strand.

24. Find the complementary strands base order:
Original strand:
AATGCCGTTAATCGAT

25. Answer: The complementary strand (underneath the original) would be:
AATGCCGTTAATCGAT
TTACGGCAATTAGCTA
(New Strand)

26. DNA is copied in a process called replication

27. When a mistake is made during replication, it is called a mutation

28. Mutations can be
very helpful,
harmful, or have
no effect on
an organism

29. Proteins are made of amino acids.
Proteins may be made of hundreds or thousands of amino acids.

30. The section of DNA on a chromosome that directs the making of a specific protein is called a gene.

31. Genes control proteins that build cells and tissues.
The gene gives directions for the order in which amino acids will be arranged.

32. Remember proteins are made on ribosomes in the cytoplasm of a cell?

33. The codes for making proteins are carried from the nucleus to the ribosomes by RNA.

34. RNA is made up of only one strand.
RNA contains a nitrogen base called uracil (U) instead of thymine (T) and the sugar ribose (instead of deoxyribose).

35. There are two kinds of RNA: transfer RNA (tRNA) and messenger RNA (mRNA).

36. Protein assembly begins as mRNA moves out of the nucleus and attaches to the ribosomes.

37. Pieces of tRNA pick up amino acids in the cytoplasm and bring them to the ribosomes.

38. tRNA temporarily matches with mRNA and the amino acids become arranged according to the code.

39. THE END!!

40. Sugar phosphate Backbone
Nitrogen bases